1. Field of the Invention
The example embodiments relate to a backlight unit (BLU) including a chip-on-board (COB) type light emitting diode (LED) module.
2. Description of the Related Art
A backlight unit (BLU) provides light for lighting a display panel in a display device. The BLU includes a light source and a light guide panel. According to an arrangement of the light source with respect to the light guide panel, the BLU may be one of an edge type in which light sources are disposed on a side surface of a light guide panel, and a direct type in which light sources are disposed right under a light guide panel.
Conventionally, a fluorescent lamp has been used as the light source of the BLU. However, recently, the fluorescent lamp is being replaced by a light emitting diode (LED). A LED is superior in terms of environmental-friendliness, lifespan, and electrical characteristics relative to a conventional fluorescent lamp. However, conventional LEDs used as light sources are packaged LEDs, where each LED includes its own separate substrate. By using a packaged LED, the connection structure between the LED module and the display panel may be inefficiently designed.
FIG. 1 is a sectional view illustrating a structure of a BLU according to a conventional art.
Referring to FIG. 1, the BLU 10 includes an LED module 12 and a light guide panel 13 which are disposed in a housing 11.
Light emitted from the LED module 12 is incident upon the light guide panel 13 disposed corresponding to a light emission direction of the LED module 12. The LED module 12 and the light guide panel 13 are separated by a predetermined distance. Due to such a separate structure, the light emitted from the LED module 12 may be partially reflected and lost. Accordingly, incidence efficiency of the light from the LED module 12 incident upon the light guide panel 13 is reduced, thereby reducing quality of the BLU 10.
The LED module 12 is manufactured by structuring an LED package in such a manner that an LED chip 12c is mounted on a package substrate 12b one by one, and then electrically bonding a plurality of the LED packages on a substrate 12a. Use of the package substrate 12b and the substrate 12 increases the number of processes and manufacturing cost of the LED module 12. Consequently, reducing an outer thickness of the BLU 10 is limited.